GS650GT setting the timing

[Antonius]

GS650GT, I cannot seem to set the timing on the exact timing marks. The timing chain is new, but the chain guides front and rear are not, although wear was not too bad (35k mile engine). On the exhaust cam with the 2 arrow pointing straight up perpendicular to cam and the 1 arrow exactly in line with the top of the engine, the 1&4 TDC is not exactly on the T mark, but in-between the T and F. The distance of travel for the chain to align this is less than that between two chain pins, about half way between two pins, so cannot adjust by this moving chain on the sprocket.
How critical is it for these timing marks to be spot on, as it is with it being closer to the F, I assume timing will be slightly advanced, do you think it will be OK?

[Nessism]

The cams should be timed by 1) align 1-4 T with the mark on the crankcase, 2) the 1-- mark on exhaust cam should point forward at the gasket surface, 3) count 20 pins between the 2 and 3 arrows on the cams.

The 1 mark on the exhaust cam may point slightly above the gasket surface, but since you have a new chain it should be close. On older engines the chain elongates and the 1 will point above, but never below.

[Antonius]

The cams should be timed by 1) align 1-4 T with the mark on the crankcase, 2) the 1-- mark on exhaust cam should point forward at the gasket surface, 3) count 20 pins between the 2 and 3 arrows on the cams.

The 1 mark on the exhaust cam may point slightly above the gasket surface, but since you have a new chain it should be close. On older engines the chain elongates and the 1 will point above, but never below.

Thanks for your reply, very helpful. Following your advice, I've now set it so that with 1-4 T, the 1 arrow is pointing slightly over the gasket surface. This is the closest it's going to get.

Cheers